KR100427143B1 - Method for Transmitting and Dowloading Streaming Data - Google Patents

Abstract

PURPOSE: A streaming data transmission and download method is provided to transmit or download streaming data to/from plural distributed nodes over a P2P(Peer To Peer) network. CONSTITUTION: The method comprises several steps. A user client receives data on a node list from a connection control server(S600). The user client sets a connection to a part or all of the nodes in the list(S602). The user client determines a connection state to each node, and a sub block number to be received from each node(S604). The user client requests the connected node to transmit a corresponding sub block(S606), and receives the sub block from the connected node(S608). While receiving the sub block, the user client checks whether there exist connections for receiving all the requested sub block(S610). The user client checks whether all the sub blocks are received(S614).

Description

How to send and download streaming data {Method for Transmitting and Dowloading Streaming Data}

The present invention relates to a method for transmitting and downloading streaming data, and more particularly, to a method for transmitting and downloading streaming data from a plurality of distributed nodes.

In the early days, contents provided through the Internet were mostly low-capacity data such as documents and pictures. However, as data transmission technology and equipment are developed, multimedia contents are also actively provided. Such multimedia content is transmitted to the user client through a streaming method.

In the past, streaming data was typically transmitted from one server to a user client.

Such streaming data should be transmitted in real time. However, in the related art, since streaming data is transmitted from one server to a client, there are many cases in which a delay occurs in the transmission of streaming data when the connection between the server and the client fails or the load of the server increases. Streaming data is played through the player at the same time as it is received, so unlike the typical data file transmission delay, the quality of service (QoS) impact is high.

Meanwhile, in the conventional file download method, US Patent No. 6,339,785 discloses a method of dividing and downloading a file through a plurality of servers. According to U.S. Patent No. 6,339,785, the entire file is divided into 1 / N and files are transmitted through N servers so that the file can be stably downloaded even if one connection fails.

However, such a download method can use the file only when the entire file has been downloaded. Therefore, there is a problem in that the download method of US Pat. No. 6,339,785 cannot be used for streaming data to be reproduced simultaneously with reception.

In the present invention, to solve the problems of the prior art as described above, we propose a method for transmitting and downloading streaming data through a plurality of nodes.

Another object of the present invention is to propose a method for stably receiving streaming data from a plurality of user clients in a peer-to-peer network, and a receiving agent program installed in the user client.

It is still another object of the present invention to propose a method for stably receiving streaming data from a file transfer system through multiple servers and a receiving agent program installed in a user client.

It is still another object of the present invention to propose a method of subdividing streaming data into blocks and sub-blocks and establishing and receiving a plurality of connections.

1 is a diagram showing a simplified configuration of a streaming data transmission system to which the present invention is applied.

2 is a diagram illustrating an example of a specific network system to which the streaming data transmission method according to the present invention is applied.

3 is a diagram showing another example of a specific network system to which the streaming data transmission method according to the present invention is applied.

4 is a diagram illustrating another example of a network system to which a streaming data transmission method according to the present invention is applied.

5 is a diagram illustrating a structure of streaming data according to an embodiment of the present invention.

6 is a flowchart of a streaming data download method according to an embodiment of the present invention.

7 is a flowchart showing the operation of the connection control server according to an embodiment of the present invention.

8 is a flowchart illustrating the operation of a connection control server according to another embodiment of the present invention.

9 is a block diagram illustrating a module configuration of an agent program installed in a user client according to an embodiment of the present invention.

10 is a block diagram illustrating a detailed module configuration of a connection control module according to an embodiment of the present invention.

11 is a flowchart illustrating a process of distributing subblocks by determining a connection state according to an exemplary embodiment of the present invention.

12 is a flowchart illustrating a process in the case where there is a node that has completed sub block reception according to an embodiment of the present invention.

13 is a diagram showing the module configuration of a connection control server according to an embodiment of the present invention.

14 is a diagram illustrating a module configuration of a connection control server according to another embodiment of the present invention.

In order to achieve the above objects, according to an embodiment of the present invention, the method comprises: establishing a connection to a plurality of nodes; (B) requesting and receiving a subblock of streaming data from each node that has established the connection; (C) monitoring a reception state of each node which has established the connection; And (d) redistributing a subblock to be received by some of the nodes which have established a connection according to the monitoring result, and when receiving all subblocks included in the block of streaming data, Provided is a method of downloading streaming data which repeats steps (b) to (d) for a sub block.

According to the present invention, the method may further include determining a subblock of streaming data to be received from each node which establishes a connection.

Step (c) may monitor whether there is a connection that has completed reception.

The sub block to be received from each node may be determined by calculating a connection state evaluation index of each connection.

The connection state evaluation index may be calculated using one or a combination thereof selected from the group consisting of a round trip time with each node and an average reception speed with each node.

The step (d) may include redistributing some of the connections that are being received and subblocks to be received in the connection where the reception is completed when there is a connection that has received all the subblocks requested as a result of the monitoring.

The step (d) may include redistributing a subblock to be received in the connection with the lowest reception rate among the connection where the reception is completed and the connection where the reception is in progress.

Redistributing a subblock to be received in the connection where the reception of the requested subblock is completed and the connection with the lowest reception rate comprises: determining a reception speed of the connection where the reception has been received and the connection with the lowest reception rate; Determining the remaining number of subblocks to be received in the connection with the lowest reception rate; Determining whether the subblocks need to be redistributed as a result of the determination of the remaining number of subblocks; And if it is necessary to redistribute the sub-blocks, distributing the remaining sub-blocks to the connection where the reception is to be completed and the connection having the lowest reception rate according to the ratio of the determined reception speed.

According to another embodiment of the present invention, in a system in which a connection control server and a plurality of user clients are coupled through a network, the connection agent server is installed in the plurality of user clients and controls reception of streaming data. An agent management module providing content information and user client identification information stored in a user client to the content control server, and transmitting content request information to the connection control server when a user requests content; A node information management module configured to receive and store node list information storing content requested by a user from the connection control server; By using the node list information to establish a connection to a plurality of nodes, determine and request the sub-blocks of streaming data to be received from the connected nodes, by monitoring the reception status of the sub-blocks during the reception of the sub-blocks from the connected nodes A connection control module for redistributing sub-blocks to be received by some nodes that have established a connection; the connection control module determines whether all sub-blocks included in the block are received, and when all sub-blocks are received, receives a sub-block of the next block. A receiving agent program is provided that includes a sub-block management module that requests the connection control module to do so.

According to another embodiment of the present invention, a reception agent program installed in a client that receives streaming data from a system including a plurality of content servers and at least one connection control server, the reception agent program for controlling the reception of streaming data, the connection control A data request module for requesting transmission of streaming data to a server; A node information management module for receiving and storing list information of content servers to receive data requested by a user from the connection control server; Establishes a connection to a plurality of content servers included in the content server list information, determines and requests a subblock of streaming data to be received from the connected content servers, and receives the subblock from the connected content servers. A connection control module for monitoring a reception state and redistributing a sub-block to be received by some content servers which have established a connection; And a sub-block management module that determines whether all sub-blocks included in the block are received by the connection control module and requests the connection control module to receive a sub-block of a next block when all sub-blocks are received. A receiving agent program is provided.

According to still another embodiment of the present invention, a connection control server is connected to a plurality of user clients via a network, and controls a connection between user clients such that the user client connects with the plurality of other user clients to receive streaming data. And a mesh configured to receive content information stored in each user client and address information of the user client from the connected plurality of user clients, and provide node information storing the requested content to the user client requesting content transmission. Control module; And a mesh information database storing content information stored by each user client received by the mesh control module and address information of the user client, wherein the plurality of user clients are provided with a receiving agent. A subblock to establish a connection to a plurality of nodes using the provided node information, determine and request a subblock of streaming data to be received from the connected nodes, and monitor the reception state of the subblock at each connected node to receive the subblock. A connection control server is provided for controlling the user client to redistribute this.

A connection control server connected to a plurality of content servers and user clients through a network, and controlling the connection between the user client and the content servers such that the user client connects to at least two content servers to receive streaming data. A server state determination module configured to receive state information from a plurality of content servers, and determine a state of each content server; When receiving the content request information from the user client, a server list providing module for providing the content server list information for receiving the streaming data of the requested content to the user client, the user client is provided with a receiving agent, The receiving agent establishes a connection to at least two content servers by using the provided server list information, determines and requests a subblock of streaming data to be received from the connected content servers, and a subblock at each connected node. A connection control server is provided for controlling a user client to monitor the reception state of the network and redistribute the sub-blocks to receive.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the streaming data download method according to a preferred embodiment of the present invention.

1 is a diagram illustrating a brief configuration of a streaming data transmission system to which the present invention is applied.

As shown in FIG. 1, the streaming data transmission system according to the present invention may include a plurality of nodes 100, 102, 104, 106, 108, and 110 and a user client 112.

The user client 112 establishes a connection with the selected plurality of nodes 102, 106, and 108 to receive the streaming data.

In FIG. 1, a plurality of nodes 100, 102, 104, 106, 108, and 110 store content data, receive a content transmission request signal from a user client, and transmit the requested content to the user client. A node may generally be a server that delivers content or may be another user client.

The user client 112 transmits a content request signal to the plurality of nodes 102, 106, 108 requesting content transmission, and receives content streaming data from the corresponding nodes 102, 106, 108. That is, according to the present invention, streaming data is received from a plurality of paths through a plurality of nodes.

At this time, the user client requests different streaming data from each node to which the connection is established, and combines the streaming data received from the plurality of nodes.

5 is a diagram illustrating a structure of streaming data according to an embodiment of the present invention.

As shown in FIG. 5, the streaming data according to an embodiment of the present invention consists of a plurality of blocks 500, and each block 500 includes a plurality of sub blocks 502.

It will be apparent to those skilled in the art that blocks and subblocks are logical units for dividing the entire streaming data and that other terms may be used.

Unlike normal file reception, streaming data must be received and played at the same time. Therefore, the conventional method of receiving a file by dividing the whole file into several parts cannot be used, such as the file reception by a multipath. This is because when a file is received through a multipath as in the prior art, the file cannot be played unless all of the file is received.

Therefore, according to the present invention, the entire streaming data is subdivided into block units, and sub blocks included in the block are received in a parallel / distributed manner through a multipath.

For example, in a system in which a connection is established as shown in FIG. 1, when a block is composed of 10 subblocks, the user client 112 may transmit subblocks 1 to 3 and a fourth node to the second node 102. 106) requests sub blocks 4-7, and subblocks 8-10 for the fifth node 108.

When all the subblocks included in one block are received, the user client 112 requests the subblocks included in the next block. Since the data of the next block is received after receiving all of one block data, even if the data is received through multiple paths, it is possible to support a streaming service that plays data at the same time as the data is received.

In FIG. 5, only streaming data is divided into blocks and sub blocks, but it will be apparent to those skilled in the art that streaming data may be divided and transmitted in smaller units than sub blocks.

When the user client requests a subblock from each connected node, the user client determines the connection state with each node and requests the subblock. For example, if the second node 102, the fourth node 106, and the fifth node 108 have the best connection state of the second node and the fifth node connection state is the worst, the user client ( 112 requests the largest number of subblocks from the second node 102 and the smallest number of subblocks from the fifth node. A method of determining a connection state with each node and distributing a subblock to be requested accordingly will be described later in detail through a separate drawing.

When receiving a sub block included in a block through a plurality of paths, if reception is completed in some paths but reception is continued in another path, the path where the transmission is completed does not receive data until reception of another path is completed. Such an idle connection reduces the transmission efficiency of data.

Therefore, according to the present invention, when the reception of the subblocks in any one of the plurality of paths is completed, the subblocks which have not been received yet are received from the received paths. The process of redistributing the sub-blocks to be received when the reception is completed in one path will be described later in detail through separate drawings.

2 is a diagram illustrating an example of a specific network system to which the streaming data transmission method according to the present invention is applied.

2 illustrates a case where a streaming data transmission method according to the present invention is applied by a peer to peer (P2P) scheme.

As shown in FIG. 2, the network system to which the present invention is applied may include a connection control server 200 and a plurality of clients 202, 204, 206, 208, 210, 212, 214, and 216.

The connection control server 200 receives a content transmission request signal from the user client, and provides address information of another user client storing the corresponding content to the user client requesting the content in response to the received content transmission request signal. The user client requesting the content may receive streaming data of the content through a plurality of paths using address information provided from the connection control server 200.

For example, when the user client 210 requests the connection control server 200 to transmit a movie A, the connection control server 200 grasps user client information storing the A movie, and determines the user client's information. The address information is provided to the user client 210 requesting the content.

Here, the address information may be an IP address and a port number, and it will be apparent to those skilled in the art that other address identification means may be used.

Assume that the client storing the A movie is 202, 204, and 208 in FIG. When the connection control server provides the client 210 requesting the content with the client 202, 204, and 208 storing the A movie, the client 210 requesting the content is configured with the clients 202 storing the A movie. 204, 208 to establish a connection.

When the connection is established, the user client 210 requests different subblocks from the clients 202, 204, and 208 to which the connection is established. When all sub blocks included in the block are received, the user client 210 requests the sub block of the next block. The transmitted streaming data is stored in the user client 210, and transmits the stored data when a transmission request of another client is made.

Each client is equipped with a receiving agent program for communicating with other clients or a connection control server. In this embodiment, the case where the receiving agent is computer software will be described. However, it will be apparent to those skilled in the art that the receiving agent may be implemented in a form of a device or a card other than the software and installed in the user client.

When the client is powered on or the installed agent program is executed, the agent program transmits the content information stored in the user client to the connection control server 200, and the connection control server stores the transmitted information.

3 is a diagram illustrating another example of a specific network system to which the streaming data transmission method according to the present invention is applied.

3 illustrates a case where streaming data is provided through multiple servers.

As shown in FIG. 3, the streaming data transmission system according to an embodiment of the present invention uses a plurality of content servers 300, 302, 304, 306, and 308, a connection control server 310, and a user client 312. It may include.

The connection control server 310 receives a content transmission request signal from the user client 312 and provides information of a server to which the user client 312 accesses among the plurality of content servers 300, 302, 304, 306, and 308. Do it.

The connection control server 310 periodically receives state information from the content servers 300, 302, 304, 306, and 308, and allows the user client to access a server having a good state by referring to the received state information.

The user client 312 receives server list information from the connection control server 310 to establish a connection with the content servers in the list, and receives streaming data through multiple paths.

As in the case of FIG. 2, the receiving agent program is installed in the user client for receiving streaming data through the multipath. Detailed module configuration of the receiving agent program will be described later in detail through separate drawings.

4 is a diagram illustrating another example of a network system to which a streaming data transmission method according to the present invention is applied.

4 is a system in which the P2P system of FIG. 2 and the multi-server data transmission system of FIG. 3 are combined.

As shown in FIG. 4, the streaming data transmission system according to an embodiment of the present invention includes a connection control server 410, a plurality of content servers 400, 402, 404, 406, and 408 and a plurality of clients 412. , 414, 416, 418, 420, 422, 424, 426, 428.

In FIG. 4, the connection control server 410 receives the content request information from the user client, and provides the client that stores the content requested by the user or the content server list information to the client that requested the content.

The user programs 412, 414, 416, 418, 420, 422, 424, 426, 428 are installed with the agent program as in the case of FIGS. 2 and 3, and the client is powered on or the agent program is executed. The content information stored in the transmission is transmitted to the connection control server 410.

The user client requesting the content establishes a connection to the client or the content server included in the list information provided by the connection control server 410, and receives streaming data by requesting different sub-blocks from the connected client or the content server.

2 to 4 have been described with respect to a system capable of receiving streaming data through a multi-path, in addition to the system of Figures 2 to 4 in addition to the system for transmitting data through a plurality of nodes in the streaming data transmission according to the present invention And it will be apparent to those skilled in the art that a download method can be used.

6 is a flowchart of a streaming data download method according to an embodiment of the present invention.

As shown in FIG. 6, the user client first receives node list information from the connection control server (S600). In the system of FIG. 2, a node is a user client that stores content. In the system of FIG. 3, a node is a plurality of content servers. In the system of FIG. 4, a node may be a user client or a content server.

Upon receiving the node list information, a connection is established with some or all of the nodes present in the list (S602). According to a preferred embodiment of the present invention, the client establishes a TCP connection to the node, and other connection establishment schemes may be used. If the connection setup fails, the node information that failed to connect is stored in the black list queue, and subsequent connections are not established for the nodes stored in the black list queue.

When the connection is established, the connection status with each node is determined to determine a subblock number to be received from each node (S604).

According to an embodiment of the present invention, the connection state with the nodes is determined by using a round trip time with each node or a reception speed at each node.

According to another embodiment of the present invention, the connection control server may provide status information of nodes. In the streaming data transmission system using multiple servers as shown in FIG. 3, the connection control server provides status information of each server to the client.

According to another embodiment of the present invention, in the initial stage of access, it is possible to determine a subblock to be received from nodes without determining state information. For example, if streaming data is received from three nodes and one block is composed of fifteen subblocks, five subblocks are requested to each node.

When the sub block to be received from each node is determined, request transmission of the corresponding sub block to the connected nodes (S606). A subblock of all connected nodes may be requested, and some of the connected nodes may be requested to transmit a subblock.

The client receives the requested subblock from the connected nodes (S608). Although not shown in FIG. 6, the client determines whether there is a reception error when the subblock is received. According to an embodiment of the present invention, a checksum value of a subblock is checked to determine whether there is a reception error.

Of course, after receiving all the blocks, the reception error may be checked using the checksum value of the block.

During the reception of the subblock, it is determined whether there is a connection that has received all the requested subblocks (S610).

If there is a connection that has received all the sub-blocks, the client redistributes the unreceived sub-blocks to the corresponding connection so that the received connection does not become an idle state and receives the redistributed sub-blocks. A method of redistributing the sub-blocks will be described later in detail through separate drawings.

The client determines whether all subblocks included in the block are received (S614).

When all the sub blocks are received, the process of determining the sub block number of the next block to be received from each node is repeated in order to receive the sub blocks of the next block from the multipath (S604).

If all sub blocks are not received, steps S610 to S614 are repeated until all sub blocks are received.

As described with reference to FIG. 6, according to the present invention, when reception is completed in any one of the multiple paths, the idle connection is prevented from occurring by redistributing and receiving a subblock to be received by each node. Therefore, the reception efficiency of data can be improved.

Although FIG. 6 illustrates a case of redistributing a subblock to be received among nodes currently receiving streaming data, the connection is established but the status of nodes not receiving a request for transmission of the subblock is monitored to transmit data. It will be apparent to those skilled in the art that subblocks may be redistributed between nodes and nodes that do not transmit data.

In addition, although not shown in FIG. 6, if the streaming data cannot be received through the plurality of nodes, a process of switching the reception mode to receive the streaming data in a general manner through a single server may be further included.

7 is a flowchart illustrating an operation of a connection control server according to an exemplary embodiment of the present invention.

The operation of the connection control server shown in FIG. 7 illustrates the operation of the connection control server in a P2P network as shown in FIG. 2 or a network in which P2P and multiple servers as shown in FIG. 4 are mixed.

As shown in FIG. 7, the connection control server receives content information stored in the node and address information of the node from the connected nodes (S700). As described above, a reception agent program is installed in each user client (node) of the P2P network, and the reception agent program transmits content information stored in the user client and address information of the user client to the connection control server. The address of the received node and the content information stored in the node are stored in the database of the connection control server.

The connection control server receives content request information from connected nodes (S702). After receiving the content request information, the connection control server uses the information received and stored in step S700 to inquire nodes storing the requested content (S704).

The connection control server provides node list information storing the requested content to the requesting client (S706).

Although not shown in FIG. 7, the connection control server may receive state information (eg, PING information) from nodes, and provide the received node state information together with the node list information.

When receiving node status information from the connection control server, the user client selects a node to establish a connection based on the received status information. If the connection setup fails or the data reception rate is poor, a new connection is attempted using the node status information. Select the node to do. This node state information can be updated continuously, and the updated information is sent to the user client requesting or receiving data transmission.

8 is a flowchart illustrating an operation of a connection control server according to another embodiment of the present invention.

FIG. 8 illustrates an operation of a connection control server in a streaming data transmission network using multiple servers as shown in FIG. 3.

As shown in FIG. 8, the connection control server receives state information from each content server (S800). According to a preferred embodiment of the present invention, the state information may be any one selected from the group consisting of bandwidth information, CPU utilization information, memory utilization information, accessor information and file I / O information, or a combination thereof. It will be apparent to those skilled in the art that other than the above information may be used as the status information of the server.

The connection control server receives content request information from the user client (S802).

After receiving the content request information, the connection control server refers to the state information received in the step S800, address information (ie, node list information) and sub-block distribution information (ie, any sub server of each content server) of good content servers. Information on whether to receive the block) is provided to the client that requested the content (S804).

In FIG. 8, the connection control server provides the user client with sub block distribution information. However, the user client may distribute a sub block to be received by checking a connection state after connecting to each content server.

Alternatively, the sub-block distribution information is provided by the connection control server at the beginning of the reception, but after the reception of one block is completed, the user client knows the reception speed with each content server. May distribute sub-blocks to receive from each content server to receive.

9 is a block diagram illustrating a module configuration of an agent program installed in a user client according to an exemplary embodiment of the present invention.

As shown in Figure 9, the receiving agent program according to an embodiment of the present invention is the agent management module 900, cache management module 902, connection control module 904, node management module 906, block management Module 908 and sub-block management module 910.

In FIG. 9, the agent management module 900 is in charge of communication with the connection control server. When the user client is turned on or the agent program is executed, the agent management module 900 includes user client information including the IP address and port number of the user client and the user client. Provides the stored content information to the connection control server.

In addition, when the user requests content transmission, the agent management module 900 transmits content request information to the connection control server. If meta information is required to play the requested content, the meta information of the requested content may be provided to a player to play the content.

The cache management module 902 is a module for managing streaming data received from nodes. The cache management module 902 stores information on the amount of cache currently remaining and the contents of the cache, and provides the stored information to the agent management module 900 when the user client is turned on or the agent program is executed. do. According to a preferred embodiment of the present invention, the cache management module stores the received streaming data in a scrambled state.

The connection control module 904 functions to establish a connection to a predetermined number of nodes by using node list information received from the connection control server. The connection control module 904 determines the connection state information with each node, distributes a subblock to be received from each node, and requests the subblocks from each node according to the distribution result.

In addition, the connection control module 904 continuously monitors the reception states of the established connections with each node, and redistributes the sub-blocks to be received in some of the established connections according to the monitoring result.

According to a preferred embodiment of the present invention, the connection control module 904 monitors whether there is a connection that has completed reception among the established connections with each node, and, if there is a connection that has completed reception, Redistribute the sub-blocks to be received on some of the connections that have not been received so that idle connections do not occur.

According to another embodiment of the present invention, the sub-block may be redistributed in advance according to the reception status of each connection even if the reception completion of the connection does not exist using the reception state information of each connection.

According to another embodiment of the present invention, the connection control module 904 monitors state information of a node that does not transmit data among the nodes for which a connection is established, and a portion of a node not transmitting data and a node transmitting data. It is also possible to redistribute the subblocks to be received in part of.

The node management module 906 functions to provide node connection information provided from the connection control server to the connection control module 904. As described above, the node list information may include an IP address and a port number of the node. When the user requests content, the agent management module 900 requests node information storing the content requested by the user to the connection control server, receives the node list information, and provides the node list module to the node management module 906. Node information is constantly updated because the nodes storing content may be powered off or unstable.

The sub block management module 910 receives a sub block from nodes, and determines whether all sub blocks included in the specific block have been received. When all the sub blocks are received, the sub block management module 910 provides the block management module 908 in which reception has been completed. If the sub block management module determines that all sub blocks included in one block are received, the connection control module requests and receives the sub blocks of the next block.

The block management module 908 functions to provide block data, which has been received, to a player or cache management module that reproduces streaming data.

Although not shown in FIG. 9, the reservation management module may be further included in the receiving agent program. When streaming data is transmitted at high speed, the user's Internet connection environment may not be able to keep up with this transmission speed. Therefore, in this case, a reservation is made before the movie is played directly so that the movie data is stored in the cache in advance, and the reservation management module performs a process for such reservation.

The reservation management module manages the information on whether the user has received the streaming data requesting the reservation and the requested data, and requests necessary data through the connection control module until all the requested data is received.

10 is a block diagram showing a detailed module configuration of a connection control module according to an embodiment of the present invention.

As shown in FIG. 10, the connection control module according to an embodiment of the present invention includes a connection setting module 1000, a connection state determination module 1002, a sub block distribution module 1004, and a reception state monitoring module 1006. It may include.

The connection establishment module 1000 functions to establish a connection to nodes that will receive data by using node list information provided by the connection control server. The connection setup may be a process in which a user client requests a TCP connection to a node, determines whether the node can accept the TCP connection, and permits the TCP connection. Of course, it has already been described above that other connection establishment methods may be used in addition to the TCP connection.

The connection state determination module 1002 determines a connection state with each node to which a connection is established. The connection state determination module 1002 calculates a connection state evaluation index with each node to determine the connection state.

According to an embodiment of the present invention, the connection state evaluation index may be calculated using the round trip time with each node.

According to another embodiment of the present invention, the connection state evaluation index may be calculated using the reception speed with each node, or may be calculated in consideration of the round trip time and the reception speed together.

Since the reception speed is not known at the time of initial data reception, the connection status evaluation index is calculated using the round trip time, and if the data reception progresses and the reception speed is known, the connection status evaluation index is calculated using the reception speed. It is desirable to. Since the reception speed is constantly changing, the connection state evaluation index is also continuously updated.

According to another embodiment of the present invention, the connection state determination module may receive state information of nodes from a connection control server, and determine the connection state using the received state information.

The sub block distribution module 1004 distributes a sub block to be received from nodes to which a connection is established using the connection state evaluation index calculated by the connection state determination module 1002. It would be desirable to determine the number of subblocks to receive from each node according to the ratio of the connection state evaluation index.

The reception state monitoring module 1006 determines whether there is a connection in which reception of a sub block is completed among the connections established with each node, and if there is a connection in which reception is completed, the sub block to be received by the sub block distribution module 1004. Request redistribution of blocks.

If the subblocks are redistributed to all nodes that are connected, efficiency may be reduced since control signals must be transmitted to all nodes again. Therefore, according to a preferred embodiment of the present invention, it is preferable to redistribute the sub-blocks only for the connection where the reception is completed and the connection with the lowest reception rate. In this case, the control signal for sub-block redistribution may be transmitted only on the connection where the reception is completed and the path with the lowest reception rate.

11 is a flowchart illustrating a process of distributing sub blocks by determining a connection state according to an exemplary embodiment of the present invention.

As shown in FIG. 11, at the initial reception, a round trip time with each node to which a connection is established is measured (S1100). The round trip time refers to the time taken to transmit a check signal to a connected node and receive a response signal.

After the measurement of the round trip time, it is determined whether the connection knows the average reception speed information of all the established connections (S1102). If several blocks are already received, the average reception speed information on all paths will be known.

If the average reception speed of all connections is known, the connection state evaluation index is calculated using the average reception speed information (S1104). For example, if streaming data is received through three nodes, and the average reception speed of each connection is 500,000bps, 100,000bps, and 64,000bps, the connection state evaluation indexes of each connection are set to 500,000, 100,000, and 64,000. Of course, the normalized average reception speed may be used as the connection state evaluation index.

If the average reception speed of all the connections is not known, it is determined whether the average reception speed information of some of the connections is known (S1106). This case may occur when streaming data is received through a new node while receiving streaming data.

If the average reception speed information of some connections is known, the connection state evaluation index is calculated using the round trip time and the average reception speed (S1108).

For example, streaming data is received through three nodes, an average reception speed of the first node of the three nodes is 200,000bps, an average reception speed of the second node is 100,000bps, and an average reception speed of the third node. Assume that the information is unknown. In addition, it is assumed that the round trip time of the first node is 23ms, the round trip time of the second node is 32ms, and the round trip time of the third node is 20ms.

At this time, the connection state evaluation index is calculated by (reception speed) / (round trip time). In this case, the average reception speed of the third node is predicted using the value of the connection having the smallest value of the connection that calculates the (reception speed) / (round trip time). Since the value of calculating (reception speed) / (round trip time) of the second node is the smallest, the average reception speed of the third node may be calculated as in Equation 1 below.

If you do not know the average reception speed information of all nodes, the round trip time is used to calculate the performance index. According to an embodiment of the present invention, the inverse of the round trip time may be used as a performance index.

For example, suppose that you receive streaming data over three nodes, and the round trip times for each node are 23ms, 41ms, and 32ms. In this case, the performance index for each connection is This could be

Computing the performance index for each connection, it is determined whether to receive a number of sub-blocks of the total sub-blocks included in the block from each node.

The number of subblocks to receive from each node will be determined by the ratio of the connection state evaluation index. In more detail, the number of subblocks to be received from each node may be calculated as in Equation 2 below.

, where i = 1 to n-1

, where i = n

Where P_i is the number of subblocks to request for each connection, and alpha_i is the performance index of each connection. That is, the user client requesting the sub block requests the sub block from each node by the calculated P_i.

12 is a flowchart illustrating a process in the case where there is a node that has completed subblock reception according to an embodiment of the present invention.

As shown in FIG. 12, the reception state monitoring module of the connection control module monitors whether there is a connection in which reception is completed (S1200).

If there is a connection for which reception has been completed, a connection having the lowest reception rate among the connections for which reception has not yet been completed is searched for (S1202). Here, the reception rate may be calculated by (number of subblocks received) / (number of subblocks requested).

After finding the connection with the lowest reception rate, the number of subblocks to be received in the connection with the lowest reception rate is calculated (S1204).

After calculating the number of remaining subblocks, it is determined whether a connection with a low reception rate and a connection where reception is completed need to be redistributed and received (S1206). For example, it may not be necessary to redistribute the sub-blocks if all remaining sub-blocks can be received during the time for sending the control signal for sub-block redistribution.

If it is determined that subblock redistribution is necessary, the number of subblocks to be received by the connection with the lowest reception rate and the connection with the lowest reception rate is redistributed according to the connection state evaluation index (S1208).

Redistribution of the sub blocks may be performed as in Equation 3 below.

P_2 = (number of remaining subblocks)-P_1

Where P_1 is the number of newly allocated subblocks for low-receive connections, alpha_1 is the performance index for low-received connections, P_2 is the number of newly allocated subblocks for complete connections, and alpha_2 is the complete connection. The connection state judgment index of.

When the sub block is redistributed, the sub block is re-requested to the node corresponding to each connection according to the distribution criteria (S1210). When the calculation result indicates that the sub block no longer needs to be received in the connection with a low reception rate, the node is requested to stop transmitting the sub block.

13 is a diagram illustrating a module configuration of a connection control server according to an exemplary embodiment of the present invention.

FIG. 13 illustrates a module configuration of a connection control server in a P2P network as shown in FIG. 2 or a network in which multiple servers and P2P as shown in FIG. 4 are mixed.

As shown in FIG. 13, the connection control server according to an embodiment of the present invention may include a mesh management module 1300, a node information providing module 1302, and an authentication module 1304. User database 1306, meta information database 1308, and mesh information database 1310 may be combined.

In FIG. 13, the mesh management module 1300 manages information of connected user clients. As described above, when the client is powered on or the receiving agent program is executed, the client's address information and stored content information are transmitted to the connection control server, and the mesh management module 1300 receives the information and transmits the mesh information database. (1310).

When the user requests the transmission of specific content, the node information providing module 1302 queries the mesh information database 1310 to extract information about the node that stores the content, and provides the extracted information to the user client who requested the content transmission. .

The authentication module 1304 functions to authenticate the user requesting the content and to process the charging information. When a user requests content, authentication key information including a user ID and a password is transmitted to the connection control server, and the authentication module 1304 determines whether the user is a registered user. In addition, the authentication module 1304 is connected with an external billing server (not shown) to determine whether the user who requested the content pays the amount according to the content request.

The user database 1306 stores IDs, passwords, personal information, and the like of registered users, and the meta information database 1308 stores information about a coding method, an author, and the like of the content. When the user who requested the content is authenticated, the mesh management module 1300 provides meta information of the requested content to the user who requested the content. In general, meta information is information necessary for reproducing streaming data. However, if data can be reproduced without meta information, the meta information database 1308 may not be provided.

The mesh information database 1310 stores a user client connected to the connection control server 1310 and content information stored in the user client.

14 is a diagram illustrating a module configuration of a connection control server according to another embodiment of the present invention.

As shown in FIG. 14, the connection control server according to another embodiment of the present invention may include a server state determination module 1400, a sub block distribution module 1402, a server list providing module 1404, and an authentication module 1406. User database 1408, content server database 1410, and meta information database 1412 may be combined.

The server state determination module 1400 is a module that determines state information of content servers managed by the connection control server. As described above, the server state determination module 1400 determines the state of each content server using bandwidth information, CPU utilization information, memory utilization information, accessor information, file I / O information, and the like.

The server list providing module 1404 provides a list information of a content server to which a user client connects to a user client requesting content. The server list providing module provides a list of servers having good status to the user client by using the determination result of the server state determining module.

The sub-block distribution module 1402 functions to provide the user client with information about the number of sub-blocks that the user client should receive from each content server by using the state determination result of each content server. Of course, it has already been described above that the distribution of sub-blocks may be made in the user client.

The content server database 1410 stores information about a content server managed by the connection control server.

Since the functions of the authentication module 1406 and the information stored in the user database 1408 and the meta information database 1412 are the same as those of FIG. 13, description thereof will be omitted.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, according to the streaming data transmission and download method according to the present invention, since streaming data is transmitted through multiple paths, there is an advantage in that a stable streaming service can be provided even when an error occurs in any one node. .

In addition, according to the present invention, when the reception is completed on any one connection, the sub-blocks to be received are redistributed and requested, thereby preventing generation of idle connections, thereby improving reception efficiency of streaming data.

In particular, the present invention may be usefully used when receiving streaming data through a plurality of nodes in a P2P network.

Claims (38)

Establishing a connection to the plurality of nodes (a); (B) requesting and receiving a subblock of streaming data from each node that has established the connection; (C) monitoring the reception status of the established connections; And (D) redistributing a subblock to be received by some of the nodes which have established a connection according to the monitoring result, When receiving all of the sub-blocks included in the block of streaming data, repeating the steps (b) to (d) for the sub block of the next block, characterized in that for downloading the streaming data. The method of claim 1, And determining a sub-block of streaming data to be received from each node which has established a connection. The method of claim 1, The step (c) is a method for downloading streaming data, characterized in that for monitoring whether there is a connection that has completed reception. The method of claim 2, The sub-block to be received from each node is determined by calculating the connection state evaluation index of each connection. The method of claim 4, wherein The connection state evaluation index is calculated using any one or a combination thereof selected from the group consisting of a round trip time with each node and an average reception speed with each node. The method of claim 3, Wherein step (d), if there is a connection that has received all the sub-blocks requested as a result of the monitoring, redistributing a part of the connection in progress and the sub-blocks to be received in the connection is received; How to download. The method of claim 6, The step (d) includes redistributing the sub-blocks to be received in the connection with the lowest reception rate among the connection where the reception is completed and the connection in which the reception is in progress. The method of claim 7, wherein Redistributing a subblock to be received in the connection where the reception of the requested subblock is completed and the connection with the lowest reception rate, Determining a reception speed of the connection where the reception is completed and the connection with the lowest reception rate; Determining the remaining number of subblocks to be received in the connection with the lowest reception rate; Determining whether the subblocks need to be redistributed as a result of the determination of the remaining number of subblocks; And If it is necessary to redistribute the sub-blocks, distributing the remaining sub-blocks to the connection where the reception is completed and the connection with the lowest reception rate according to the ratio of the determined reception speed. Way. The method of claim 1, If the connection setup fails, storing the node information that failed to establish the connection to the black list queue further comprises the step of downloading the streaming data. The method of claim 2, And receiving state information of a node, wherein a sub block to be received from each node that has established a connection is determined using state information of the received node. The method of claim 2, In the initial stage of reception, the sub-blocks to be received by each node are determined by using the status information of the received nodes.After the reception speed of each node is determined, it consists of a round trip time with each node and an average reception speed with each node. And determining a sub block to be received using a connection state evaluation index calculated using any one selected from the group or a combination thereof. The method of claim 10, The step (a) is to download the streaming data, characterized in that to establish a connection to a plurality of nodes using the state information of the receiving node. The method of claim 1, And determining a reception error by using the checksum value of the received subblock. The method of claim 1, And after the sub-blocks have been distributed, re-requesting and receiving the sub-blocks from the corresponding nodes according to the distribution criteria. The method of claim 1, The method of downloading streaming data further comprising the step of receiving streaming data by connecting to a single server when it fails to receive sub-blocks from a plurality of nodes. The method of claim 1, Monitoring status information of nodes which do not transmit data among the connected nodes; And Redistributing sub-blocks to be received by some of the nodes of the connection in which reception is in progress and some of the nodes not transmitting the data according to the monitoring result. A receiving agent program installed in the plurality of user clients in a system in which a connection control server and a plurality of user clients are coupled through a network, for controlling reception of streaming data, An agent management module providing content information and user client identification information stored in a user client to the connection control server, and transmitting content request information to the connection control server when a user requests content; A node information management module configured to receive and store node list information storing content requested by a user from the connection control server; By using the node list information to establish a connection to a plurality of nodes, determine and request the sub-blocks of streaming data to be received from the connected nodes, by monitoring the reception status of the sub-blocks during the reception of the sub-blocks from the connected nodes A connection control module for redistributing sub-blocks to be received by some nodes which have established a connection; And a sub-block management module for determining whether all sub-blocks included in the block are received by the connection control module and requesting the connection control module to receive a sub-block of a next block when all sub-blocks are received. Receiving agent program. The method of claim 17, And the connection control module redistributes the sub-blocks to be received in a part of the connection where the reception of the requested sub-block is completed and a part of the connection in progress. The method of claim 18, The connection control module, A connection establishment module for establishing a connection to nodes included in the node list; A connection state determination module that determines a connection state of nodes which have established a connection in the connection setting module; A sub-block distribution module for distributing sub-blocks to be received from nodes to which a connection is established by using connection state information of the connection state determination module; A reception state monitoring module for requesting the sub-block distribution module to redistribute the sub-blocks for the connection where the reception is completed and the connection with the lowest reception rate, when there is a node in which the requested sub-block is completed among the nodes in which the connection is established , And the subblock distribution module redistributes the subblocks to be received according to the reception speed of the connection where the reception is completed and the connection with the lowest reception rate in response to a request of the reception state monitoring module. The method of claim 19, And the connection state determination module determines the connection state using one or a combination thereof selected from the group consisting of a round trip time with each connected node and a reception speed with each node. The method of claim 19, And the connection state determination module receives node state information from the connection control server to determine a connection state. The method of claim 19, The connection establishment module establishes a connection using node state information provided from a connection control server, and if the connection establishment fails, establish a connection to another node using the node state information. The method of claim 19, If the connection establishment module fails to establish a connection, the receiving agent program, characterized in that for storing the node information in the black list queue. The method of claim 17, And the sub block management module determines a reception error by using a checksum value of the received sub block. The method of claim 17, And a cache management module that stores and manages the received streaming data in a scrambled state. The method of claim 25, And a block management module for providing block data to the cache management module or a player playing the streaming data when all sub-blocks included in the block are received. The method of claim 17, And a reservation management module which transmits reservation request information to the connection control server and manages received reservation content information. The method of claim 17, The connection control module, Monitoring status information of nodes that do not transmit data among the connected nodes, and redistributing sub-blocks to be received by some of the nodes that do not transmit data and some of the nodes that transmit data according to the monitoring result. Receive agent program. A receiving agent program installed in a client that receives streaming data from a system including a plurality of content servers and at least one connection control server, the reception agent program controlling the reception of streaming data. A data request module for requesting transmission of streaming data to the connection control server; A node information management module for receiving and storing list information of content servers to receive data requested by a user from the connection control server; Establishes a connection to a plurality of content servers included in the content server list information, determines and requests a subblock of streaming data to be received from the connected content servers, and receives the subblock from the connected content servers. A connection control module for monitoring a reception state and redistributing a sub-block to be received by some content servers which have established a connection; And And a sub-block management module for determining whether all sub-blocks included in the block are received by the connection control module and requesting the connection control module to receive a sub-block of a next block when all sub-blocks are received. Receiving agent program. The method of claim 29, And the connection control module redistributes the sub-blocks to be received in a part of the connection where the reception of the requested sub-block is completed and a part of the connection in progress. The method of claim 30, The connection control module, A connection establishment module configured to establish a connection to content servers included in the content server list; A connection state determination module that determines a connection state with content servers that have established a connection in the connection setting module; A sub-block distribution module for distributing sub-blocks to be received from content servers to which a connection is established using connection state information of the connection state determination module; And a reception state monitoring module for requesting the sub-block distribution module to redistribute the sub-blocks for the connection where the reception of the requested sub block is completed among the established connections and the connection with the lowest reception rate. , And the subblock distribution module redistributes the subblocks to be received according to the reception speed of the connection where the reception is completed and the connection with the lowest reception rate in response to a request of the reception state monitoring module. The method of claim 29, And the connection state determination module determines the connection state using the content server state information provided from the connection control server. A connection control server connected to a plurality of user clients via a network and controlling the connection between user clients so that the user client connects with the plurality of other user clients to receive streaming data. Mesh management for receiving content information stored in each user client and address information of the user client from the connected plurality of user clients, and providing node information storing the requested content to the user client requesting content transmission. module; And Including a mesh information database for storing the content information stored in each user client received by the mesh management module and the address information of the user client, A receiving agent is installed in the plurality of user clients, and the receiving agent establishes a connection to the plurality of nodes using the provided node information, determines and requests a subblock of streaming data to be received from the connected nodes, And controlling the user client to redistribute the sub-blocks to be received by monitoring the reception status of the sub-blocks at each connected node. The method of claim 33, wherein Connection control server, characterized in that further comprising an authentication module for authenticating the connected user and processing the charging information. The method of claim 33, wherein And a meta information database storing meta information of the requested streaming data and a user database storing information of registered users. The method of claim 33, wherein The mesh management module receives state information of each node, and provides the state information together when providing the node information. A connection control server connected to a plurality of content servers and user clients through a network, and controlling a connection between the user client and the content servers such that the user client connects to at least two content servers to receive streaming data. A server state determination module configured to receive state information from the plurality of connected content servers and determine a state of each content server; When receiving the content request information from the user client, the server list providing module for providing the content server list information for receiving the streaming data of the requested content to the user client, A receiving agent is installed in the user client, and the receiving agent establishes a connection to at least two content servers using the provided server list information, and determines a subblock of streaming data to be received from the connected content servers. Requesting, and controlling the user client to redistribute the sub-blocks to be received by monitoring the reception status of the sub-blocks in each connected node. The method of claim 37, The state information provided from the content server to the connection control server is any one selected from the group consisting of bandwidth information, CPU utilization information, memory utilization information, accessor information and file I / O information, or a combination thereof. Connection control server.